The present invention relates generally to an eyeball-projection display apparatus designed to optically guide an image shown on an image display device into the eyeball of a viewer where it is enlarged as a virtual image for projection.
The eyeball-projection display apparatus known so far in the art include a head-up display used for on-board indicators, and a near-eye display that is located near the eyeball of a viewer where light rays or beams exiting out from an image shown on a display device are guided into the viewer's eyeball for viewing of enlarged virtual images.
Among the near-eye displays, the head-mounted display type having an optical system mounted on the viewer's head goes mainstream. There are also a hand-held near-eye display of the type manually held by the viewer without being mounted on the head, and a near-eye display of the type that the viewer looks in a fixed device.
Conventional optical systems in the eyeball-projection display apparatus capable of viewing in a wide field of view include an optical system of the type in which an intermediate image is formed using a relay optical system and light beams are then guided into the eyeball of the viewer by way of a back-surface mirror for viewing of an enlarged virtual image over a wide field of view, as known from the following publications (JP(A) 2012-208193 and JP(A) 7-218859).